CPU fan stuck at 100% speed

Says it in the title really, the temps at idle are a reasonably frosty 25 degrees, but the fan remains a constant 100%. My bios settings have automatic thermal control on. One feature of my asus board is "Q-fan control" which should allow the MB to control the CPU fan speed ive tried this setting on and off, no difference. The cpu cooler is the standard intel one connected to a four pin fan connector. I can use speed fan to reduce the fan speeds, but i'd rather try and get the bios to do it for me.

I've had the computer a while, but im not sure whether the problem is new as i had always assumed it was my GFX card making the noise.

My guess is a quirk in the bios that might be fixed by flashing, but thats a risky process so i don't want to risk it yet.

First thing I would do would be to enter the bios and load defaults. Save settings and restart. Now enter the bios again and set any custom settings you need ie sata mode, boot order, etc. Save settings and restart and let it boot into windows. See how it works now.
You can also disable smart fan [or whatever asus calls it] then enable it after a restart.

If the above does not work, then check the asus site for any bios updates that address this issue. DO NOT flash the bios just to have the latest and greatest bios. Only flash if the update has a fix you need.

I agree with crjdriver. Bios updates are usually hard to complete. Personally I wouldn't update my bios to solve a problem like that is it is not really causing to much of a problem. If anything it is keeping the CPU nice and cool. The only problem I could see if if the fan got worn out but that wouldn't be a hard fix.

I checked the asus site and there are some bios updates that address cpu temp readings which may be why your fan runs at full speed.

If you decide to update the bios, make sure you read the instructions and FULLY understand how to flash the bios.

FWIW I never recommend using a bios flash utility that flashes from within windows. Asus has a flash utility that works while in the bios. It is called EZ flash. All you need is the bios file on a floppy disk to flash. Most of the newer boards will also update from a flash drive or a hard drive that is FAT32.

That's what i was planning to do, i've also checked about recovery, and the board claims that if you boot a system with corrupted bios it will automatically search all usb devices for a bios file, if there is one it will attempt to rewrite the chip. If that dosn't work, what is the usual procedure, for recovery, just so i can be prepared?